mould and forcing put the bulk of the slag, but leaving a coating as mentioned. When the pipe ends become plastic they are forced together, completing the weld. After cooling the mould is easily knocked off, since the slag coating prevents adhesion. To weld a pipe .takes from f to ii minutes.
In fusion welding on solid sections, in which the thermit mixture forms a casting holding the parts together, a special V-shaped mag- nesia-tar-lined crucible, open at the bottom, is used. The hole in the bottom is closed by a headed plug, covered with refractory sand, which may be pushed upward. This crucible is placed over the mould, as shown in fig. 2, the proper amount of thermit put in and ignited. After the reaction, which takes about 35 seconds, the plug in the bottom is pushed up and the molten thermit allowed to run into the mould. In this method great care is taken to keep the slag from contact with the surfaces to be welded, and consequently enough thermit must be used to fill the mould before the slag on top of the melted metal can enter.
I -FACING -JriRE SANO.jnpe CLAY. J GROUND FlftE eftlCIt
^YELLOW WAX ^ . MIXTURE OF f SHA.Rr SAND, 3 FIRE CLAV
Q IRON PUM Oft 3AND FLOUR COKE
FIG. 3. Sectional view of typical Thermit mould.
A typical mould for heavy sections is shown in fig. 3. In preparing to weld, the surfaces to be joined should be cut or set so as to be | in. or more apart. Yellow wax is then built up around the joint in the same shape as the weld is to be. Next the mould box is placed and sand rammed up round the wax, wooden patterns being placed for the pouring gate, riser and preheating gate. The mould is vented, the patterns withdrawn, and a gas or oil flame used to melt out the wax. The heating is continued until the sections to be welded are red-hot. This prevents chilling of the thermit, which is poured in after the preheating gate has been plugged. The steps in making a typical thermit weld on a locomotive frame are graphically shown in
A Fracture.
B Gap cut out for entrance
of Thermit Steel. C Thermit weld before re- moving riser and pouring gate.
FIG. 4. Steps in making a Thermit locomotive frame weld.
fig. 4. Thermit welding is largely used in repairing broken rudder frames, propeller shafts, locomotive frames, steel rolling-mill pinions and other heavy sections, but it cannot be economically used for welding thin sheet metal sections. Welds have been made where from 3,000 to 4,000 Ib. of thermit were used.
For commercial purposes there are now produced three varieties of thermit, known as plain thermit, railroad thermit and cast-iron thermit. The plain thermit is simply a mixture of aluminium and iron oxide, as already given. Railroad thermit is plain thermit with the addition of f % nickel, I % manganese and 15 % mild steel punch- ings. Cast-iron thermit is plain thermit with the addition of 3% ferrosilicon and 20% mild steel punchings. The names of these mixtures indicate their principal uses. (E. Vl.)
THOMAS, AUGUSTUS (1859- ), American playwright, was born in St. Louis, Mo., Jan. 8 1859. He was educated in the public schools, for several years worked in railway freight offices, and, after serving as special correspondent for various newspapers, became in 1889 editor and proprietor of the Kansas City (Mo.) Mirror. As a youth he had been a member of local amateur dramatic companies and had tried his hand at dramatic composition. One of these early pieces, Editha's Burglar, based on Mrs. Burnett's story of the same name, was enlarged to a four-act play and presented with great success at the Madison Square theatre in New York in 1889. This led him a little later to devote all his attention to the drama. His play Alabama
(1891), depicting the old-time South, contributed to the removal of sectional prejudice resulting from the Civil War. His numer- ous dramas include In Mizzoura (1893); The Hoosier Doctor (1898, by many considered his best); Oliver Goldsmith (1900); Soldiers of Fortune (1902) ; The Earl of Pawtucket (1903, highly successful in England) ; M rs, Leffingwell's Boots (1905); De Lan- cey (1905) ; The Embassy Ball (1905) ; The Witching Hour (1909) ; As a ManThinks(igi 2) ; M ere M an (1912) ; Indian Summerligi 2) . THOMAS, JAMES HENRY (1878- ), English Labour poli- tician, was born at Newport (Mon.), of working-class parents, Oct. 3 1878, and was educated in the board schools. He started at nine years' old as an errand boy, but he soon passed into the service of the Great Western Railway Co., first as engine-cleaner, afterwards becoming fireman and engine-driver. He was elected town councillor of the famous Great Western railway centre, Swindon, and became chairman of the Finance Committee and of the Electricity and Tramways Committee. At an early date he associated himself with the development of the policy of unions among the railway servants. He became president of the A.S.R.S. in 1910, and for many years was secretary of the National Union of Railwaymen, and the most powerful voice in deciding their policy. He was elected to Parliament in the Labour interest for the great Midland railway centre, Derby, in 1910. For some years he took no very prominent part in Parliamentary life, being actively engaged outside in the interests of his railwaymen, who, besides many smaller disputes, came out in a body in the great strike of 1911. Another matter of vast importance in which he was deeply involved, was the organization of the so-called " Triple Alliance " between the unions representing coal-miners, transport workers, and railwaymen. When the war came, he took his stand, with the bulk of the Labour leaders, on the national and patriotic side; but, like many of them, deprecated the introduction of compulsory service, until it should be clear that the necessary men could be got in no other way. In Sept. 1915 he declared in Parliament that trade unionists were ab- solutely against conscription, that to introduce it might provoke revolution. Nearly every branch of his own railwaymen's organization, he said, had not only passed resolutions against the policy, but had threatened on its introduction to stop work. There were many who questioned at the time the justice of his estimate of the workmen's feelings; and, though he renewed his vehement protest against the first Military Service bill in Jan. 1916, and though the Labour party in conference condemned the measure, there was no difficulty in applying it and no agita- tion arose for its repeal. Even against the stronger measure of the following April only nine Labour members were found to go into the lobby on the second reading. Throughout the war Mr. Thomas, while securing large advances of wages for the railway servants, used his unique influence with them in com- posing disputes and preventing any stoppage which should inter- fere with national interests; and for this considerable service he was made a privy councillor in 1917. It was a bitter blow to him when in Sept. 1918 the rank and file disregarded an agreement which the executive, of the National Union of Railwaymen had come to with the Government for an advance of 55. for adults and 2s.6d. for boys. In spite of this, there was a general strike of railwaymen in S. Wales, and the disturbance spread partially to London and elsewhere ; but the courts, on the application of the Board of Trade, prohibited the Union from paying strike pay, and the movement collapsed. In disgust at his advice being disregarded, Mr. Thomas resigned the secretaryship of the Union, but was eventually persuaded, on promises of better dis- cipline, to resume office. He approved of the subsequent decision of the Labour party to sever itself from the Coalition, and to appeal to the electorate in Dec. 1918 for independent support, announcing as his own battle-cry " No more war." He was once more returned at the head of the poll for Derby, and by a huge majority. After the war he became a more prominent figure both in Parliament and in the national life. He made a strong speech in support of the Labour amendment to the Ad- dress in 1919, stating that he stood both against Bolshevists and against profiteers. He called upon the Government to deal with
